In many high-temperature applications, such as aircraft structures, thermal sealing members are often utilized between opposing faces or parts. Typically, the thermal sealing member provides a thermal barrier that will withstand particular conditions, for example, an exposure to temperatures in excess of 1,000 degrees C. for a time in excess of 15 minutes. These opposing parts are subject to operational loaded vibration as well as repeated opening and closing during operation and maintenance procedures. As such, these thermal sealing members are subject to a high degree of wear and potential for damage.
Current techniques for manufacturing thermal sealing members include the use of multilayer materials including, for example, stainless steel spring tube, multiple layers of woven ceramic fabric, and a woven outer stainless steel mesh integrated by hand. Beyond the fabrication challenges, the stiffness of the woven outer stainless steel mesh is relatively low, which can lead to wrinkling, deformation, and subsequently degraded performance. Further, splicing and welding of the woven outer stainless steel mesh is often required to form curved or complex shapes. This splicing and welding process is extremely time consuming and laborious. In addition, these welds create wear points on the seal itself at the mating surface. In applications where the mating surface is aluminum, the woven outer stainless steel mesh can cause galvanic corrosion.
The woven outer stainless steel mesh is also limited to an operational temperature below 800 degrees Fahrenheit (approximately 427 degrees Celsius). If temperatures exceed 800 degrees Fahrenheit, the woven outer stainless steel mesh suffers from embrittlement and begins to fail exposing the underlying layers of woven ceramic fabric to the wear surface. Failure of the woven ceramic fabric exposes the underlying stainless steel spring tube to high temperatures, causing plastic deformation, compression set, and ultimate failure as a thermal barrier.
Therefore, there is a need for improved higher temperature capable thermal sealing members that permit higher operational temperatures while minimizing compression set under thermal loads and low cost methods of manufacturing the same.